US3615775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High alumina refractory composition
Assignee: Dresser Industries Inc
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Filing: 1970-06-10
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Granted: 1971-10-26
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Expires: 1990-06-10
Abstract
Abstract Ceramically bonded high alumina refractory comprising A12O3, MgO and Cr2O3, the molar ratio of the MgO to Cr2O3 between 1:1 and 2.5:1, said refractory microscopically characterized by coarse alumina grains having Cr2O3 in solid solution, said alumina grains knitted together by a solid solution of MgO.A12O3.Cr2O3 spinel.
Inventors
- 👤 Frederick J Teeter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:07
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
11 words
A method of making ceramically bonded refractory comprising the steps of:
Claim 2
Dependent Claim
11 words
tempering the batch with a temporary binder and a tempering fluid,
Claim 3
Dependent Claim
3 words
shaping the refractory,
Claim 4
Dependent Claim
28 words
A method according to claim 2 in which the alumina is sized so that at least 50 percent rests on 65 mesh and the remainder passes 65 mesh.
Claim 5
Dependent Claim
15 words
The method according to claim 2 in which the MgO and Cr2O3 are -65 mesh.
Claim 6
Dependent Claim
36 words
burning the refractory in excess of 2,800* F., whereby said refractory develops a microstructure characterized by coarse alumina grains having Cr2O3 in sOlid solution, said alumina grains knitted together by a solid solution of MgO.Cr2O3.A12O3 spinel.
Claim 7
Dependent Claim
17 words
The method according to claim 2 in which the refractory is burned in excess of 3,000* F.
References Cited (Backward Citations)
US3192058A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |